Drive assembly

ABSTRACT

A drive assembly for a motor vehicle having a stepless transmission including a driven input shaft coupled to an engine and at least one output shaft. The input and output shafts are drivingly connected through an eccentric drive provided on the input shaft. A freewheel system is provided on the output shaft. The eccentric drive and the freewheel system are interconnected by at least one connecting element. An electrical machine is selectively connected through coupling elements to the input shaft of the transmission, to the engine, or simultaneously to the input shaft and to the engine.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention concerns a drive arrangement for a motor vehicle composedof at least one transmission driveable by an engine that has a driveshaft coupleable with the engine, for example a transmission inputshaft, as well as at least one driven shaft, for example a transmissionoutput shaft, which are drivingly connected with one another.

2. Description of the Related Art

A transmission for such a drive arrangement has been proposed in WO90/05252, for example. An adjustable eccentric drive arrangement isprovided by that transmission on an input shaft that is driveable by anengine and forms a drive shaft relative to the transmission, wherein theeccentric drive arrangement is connected with two driven shafts throughconnecting-rod-like connecting elements that form output shafts relativeto the transmission. The driven shafts are driven utilizing freewheelunits, which are provided between the connecting elements and thoseshafts.

SUMMARY OF THE INVENTION

The present invention is based upon the object of improving drivearrangements, especially for motor vehicles, with a transmission thatoperates according to the previously-described basic principle in such away that an optimal operation can be made possible. It should inparticular be ensured by the invention that a secure mode of operationof a motor vehicle is possible. Furthermore, an energy-saving orfuel-saving operation of the motor vehicle should be made possible bythe configuration of the drive arrangement in accordance with theinvention. An additional object of the invention is to enable a compactconfiguration of the drive arrangement, especially the transmissioncontained therein.

The objects underlying the present invention are at least partiallyaccomplished in that the drive arrangement includes an electricalmachine, which can be selectively connected through coupling deviceseither only with the output side of the transmission or only with theengine or, however, simultaneously with the output side and the engine.The output side of the transmission can thereby be formed by at leastone driven shaft, and the engine by an internal combustion engine. Thecoupling devices connecting the at least one rotor of the electricalmachine with the output side of the transmission and/or with the enginecan be formed, for example, by freewheel units or by positive lockingcouplings, such as, for example, gear couplings or, however, byfrictionally-engaged couplings. Nevertheless, a combination ofconnecting devices of that type can also be utilized. Freewheelcouplings with clamping bodies or loop springs can also be utilized asfreewheel couplings. Furthermore couplings based on the brake bandprinciple can be utilized.

Through the previously-mentioned arrangement it can be ensured that atleast during deceleration, for example of a motor vehicle or the drivearrangement, retardation can take place by means of the electricalmachine operated as generator and/or an eddy current brake. Theretarding torque or the braking power can then be enlarged in a simpleway by connecting the engine to the electrical machine.

In an especially advantageous way the electrical machine can beconnected with the output side of the transmission through atransmission ratio unit. The transmission ratio unit can thereby have afixed transmission ratio stage, such as, for example, a gear stage, orit can be formed by such. The transmission ratio unit can neverthelessalso have a chain drive and/or a toothed belt drive. When utilizing agear stage, it can be suitable if at least one intermediate gear isutilized for adapting the direction of rotation.

It can also be suitable for many applications if the transmission ratiounit provided between the electrical machine and the output side of thetransmission has a variable transmission ratio in that, for example, thetransmission ratio unit includes a shiftable multi-step reduction gearor a stepless transmission. When utilizing a stepless transmission, itcan be constructed as a friction transmission or a stepless, belt-drivenconical pulley transmission.

Although it can be suitable if the drive means provided between theelectrical machine and the engine enables a variable transmission ratio,it is especially advantageous for many applications if those drive meansensure a transmission-ratio-free connection or connection possibility,so that the electrical machine and engine can then be directly connectedand can then rotate at the same rotational speed. When utilizing avariable transmission ratio between the electrical machine and engine,that can be constructed in a similar manner as the already-mentionedconnection means between the electrical machine and the output side ofthe transmission.

Although for many applications the electrical machine installed isdesigned or operable only as a motor or else only as a generator, itwould be especially advantageous for most applications to use anelectrical machine that can be operated as a motor as well as agenerator. Utilization of the electrical machine as a motor enables itto be utilized as a starter for an internal combustion engine and/or asa drive engine for a motor vehicle. The output design of the electricalmachine can thereby take place in such a way that it can be utilizedmerely as an auxiliary motor, which supports the internal combustionengine, and/or it can be utilized at least part of the time as the soledrive for the motor vehicle.

A mode of operation of the electrical machine as generator enables, forexample, energy recuperation when driving downhill or duringdeceleration of a motor vehicle. Furthermore, a braking or a retardationof the entire motor vehicle and/or the internal combustion engine can beensured by the generator function of the electrical machine. Theelectrical machine can have an output in the order of from 2 to 15 kW,whereby for most applications the electrical machine can have an outputin the order of magnitude of from 6 to 12 kW, so that it can then beoperated as a starter for the internal combustion engine as well as atleast an auxiliary drive and brake for the motor vehicle.

To the extent that the energy developed during recuperation operation ofthe electrical machine can no longer be stored, because, for example thebatteries are fully charged, it can be suitable in those operatingconditions to additionally use the electrical machine for cooling and/orfor heating purposes. For that purpose, the electrical machine can beconstructed in such a way that it is maintained at an acceptabletemperature by means of the cooling system of the engine. The electricalmachine can, for example, have a fluid loop that is connected to thecooling system of the engine. Cooling of the electrical machine alsomakes it possible to design it in such a way that it can be utilized asan eddy current brake. The dissipation of the excess energy possiblydeveloped can also take place by means of an electrical heating system,which, for example, is coupled with the cooling system of the internalcombustion engine. During braking operation of the electrical machine,the excess energy can be dissipated without problems in the coolingsystem of the engine, since during deceleration of the motor vehicle theinternal combustion engine produces only little heat.

Through the configuration of a drive arrangement in accordance with theinvention, it can be ensured that the electrical machine can bedrivingly connected with the output side of the transmission as well aswith the engine, so that during deceleration of the motor vehicle thebraking action of the engine and the electrical machine complement eachother. In that way, it is possible to brake the motor vehicle by meansof the electrical machine or the internal combustion engine, although,in those conditions by means of the connecting devices that areoperative between the eccentric drive and the freewheel unit, possiblyno output can be transmitted because of the existing freewheel functionof the freewheel unit.

An especially advantageous arrangement, which can ensure a compactconstruction of a drive, consists in arranging the electrical machinecoaxially relative to the drive shaft of the transmission. Thereby thatdrive shaft can form the input shaft of the transmission and can bearranged coaxially to the crankshaft of the internal combustion engine.Depending upon the application, the electrical machine can be arrangedon the side of the drive shaft facing away from the engine, or elseaxially between the engine and the transmission.

In an advantageous way, the transmission ratio unit provided between theoutput side of the transmission and the electrical machine can bedesigned in such a way that the engine and the electrical machine rotateat least near the maximum allowable rotational speed at maximum speed ofthe motor vehicle. In that way, over-speeding of the engine constructedas an internal combustion engine should especially be avoided.

The transmission ratio unit between the output side of the transmissionand the electrical machine can also be advantageously constructed insuch a way that, at the maximum speed of the motor vehicle, theelectrical machine rotates at a rotational speed that is greater thanthe rotational speed of the engine at its highest power output.

The coupling means connecting the at least one rotor of the electricalmachine with the output side of the transmission on one hand, and withthe engine on the other hand, such as, for example, freewheel units, areappropriately arranged and connected in such a way that the electricalmachine is driven by a more rapid drive existing at a certain point intime. That means, for example, that if the internal combustion enginemomentarily ensures a more rapid drive of the electrical machine thanthe drive means that exist between the output side of the transmissionand the electrical machine, the electrical machine is driven by theengine, and by the transmission side in the opposite case.

Nevertheless, it is especially appropriate if the shiftable couplingmeans, which on one hand ensure a connection between the transmissionoutput side and the electrical machine and on the other hand between theengine and the electrical machine, are arranged and connected in such away that the electric motor can only be driven by the momentarily fasterdrive when needed, so that in some operating conditions the electricalmachine can also be driven by the momentarily slower drive. Therefore, aselective driving mode of the electrical machine is possible as afunction of certain operating parameters.

It can be especially suitable for the construction of the drivearrangement if the actuation unit for adjusting the eccentric driveprovided on the drive shaft is provided coaxially to the rotor of theelectrical machine. An especially space-saving arrangement can result inthat the rotor of the electrical machine is configured at leastpartially hollow, and the actuation unit for the eccentric drive is atleast partially accommodated within the same. In an advantageous way,the actuation unit can thereby be constructed as an electric motor,whereby a transmission ratio stage, which can, for example, beconstructed planetary-transmission-like, can be provided between thethen existing adjusting motor and the actual eccentric drive.

The configuration of a drive arrangement in accordance with theinvention enables the use of a stepless transmission, which can bemanufactured in an especially simple and rational manner. In that way, acompact construction of the drive arrangement is possible wherebynevertheless high power can be transmitted. Furthermore, through thestructure of the drive arrangement in accordance with the invention,kinematics and dynamics of the drive train can be ensured, which atleast diminishes in a simple manner free forces of inertia or freetorques as a consequence of transmission or machine parts moving backand forth.

The eccentric drive provided on the drive shaft or transmission inputshaft can advantageously have a guide region that is arrangedeccentrically opposite the axis of rotation of the drive shaft, and onwhich an eccentric component is supported, on which, in turn, theconnecting element is rotatably supported. Such a construction makespossible in a particularly simple way a stepless adjustment of theeccentricity of the eccentric drive by rotating the eccentric componentrelative to the guide region likewise arranged eccentrically relative tothe axis of rotation of the drive shaft. It can be particularlyadvantageous if the eccentric drive has several eccentric units that arearranged side by side or one after the other relative to the axis ofrotation of the drive shaft. The drive shaft with the eccentric unitsprovided on it therefore operates similar to a crankshaft, the crankradius of which however is steplessly adjustable, namely between amaximum crank radius and a minimum crank radius, which preferably canalso assume the value of zero. In order to ensure that, theeccentricities of the guide regions and the eccentric componentssupported thereon are correspondingly synchronized relative to the axisof rotation of the drive shaft. The synchronization can thereby takeplace in such a way that with a corresponding rotation of the eccentriccomponent relative to the associated guide region, the centerline or theaxis of the eccentric component coincides with the axis of rotation ofthe drive shaft, whereby the previously-mentioned crank radius becomeszero and consequently no motion is transmitted to the driven shaft orthe at least one freewheel apparatus.

An especially compact construction of the transmission can arise in thatthe drive shaft has an axial recess in which an adjusting shaft engages,by means of which the eccentric component is rotatable on thecorrespondingly associated eccentric region. The axial recess is therebypreferably arranged coaxially relative to the axis of rotation of thedrive shaft. Through the telescoping of the individual components intoone another, a space-saving design of the transmission can be achieved.It is especially suitable if the eccentric component has a recess foraccommodating the guide region. The eccentric component can thereby bedirectly pivoted on the correspondingly associated guide region. It cannevertheless also be suitable to provide a support between thecomponents, such as, for example, a slide bearing.

It can be especially advantageous for the construction of thetransmission if an eccentric component forms an internal tooth system inthe recessed area. That internal tooth system can thereby be developedin such a way that it makes possible a support of the eccentriccomponent on the associated guide region over the gear tooth addendumcircle bounded by the gear tooth system.

Furthermore, it can be especially suitable if the adjusting shaft has anexternal tooth system, whereby that external tooth system can engagewith the internal tooth system of the eccentric component. Through sucha constructional arrangement a rotation of the eccentric component onthe guide region is made possible by rotation of the adjusting shaft.

An especially simple construction of the transmission can furthermore beensured when the adjusting shaft is centered or supported in the recessof the drive shaft by the sections formed by the addendum circle of theexternal tooth system.

It can be especially advantageous if the connecting element, such as,for example, a connecting rod, is rotatably accommodated on theassociated eccentric component by a roller bearing mounting. For manyapplications, a sleeve bearing can nevertheless be utilized, which iseither self-lubricating and/or is lubricated by oil circulation.

An especially compact construction of the transmission can also beensured in that at least two connecting elements are supported on acommon eccentric component. The spacing of the drive shaft and thedriven shaft that are arranged parallel to each other, the distancebetween the two swing axes of a connecting element and the freewheelunits provided on the driven shaft can thereby be coordinated with oneanother in such a way that the connecting elements associated with acommon eccentric component are aligned in the transmission in such a waythat when transmitting torque, one connecting element is pulled and theother connecting element is pushed.

It can be especially advantageous if the at least one freewheelinteracting with a connecting element and provided on the driven shafthas an outer ring, on which the connecting element is swingably linked.It is suitable if an individual freewheel is associated to eachconnecting element.

It can be especially advantageous if the distance between the drivingand driven shafts that are arranged parallel to each other, the maximumadjustable eccentricity of an eccentric drive, and the freewheelassociated with a connecting element are dimensioned and coordinatedwith each other in such a way that the maximum swing angle producible bythe connecting element on the freewheel unit lies in the order ofmagnitude from 40° to 130°, preferably in the order of magnitude from40° to 90°.

It can be especially advantageous if the eccentric component isrotatable by least 180° on the associated guide region. In anadvantageous way, the distance between the axis of rotation of the driveshaft and the centerline or axis of the eccentrically arranged guideregion can correspond to half the maximum adjustable eccentricity of theeccentric drive. The centerline or the axis of a guide region can alsohave an eccentricity relative to the axis of rotation of the drive shaftwhich corresponds to the eccentricity present between the centerline oraxis of the guide region and the centerline or axis of the associatedeccentric component. The effective radius of the eccentric drive can beset to zero by such dimensioning, whereby an infinite transmission ratiois present, which, in turn, means that no motion is transmitted to aconnecting element. The maximum effective radius of the eccentric drivecan be set through a corresponding rotation of 180° by an eccentriccomponent on a guide region, which, in turn, corresponds to the smallestadjustable transmission ratio of the transmission, which neverthelessbrings about the greatest possible movement of the at least oneconnecting element.

It can be advantageous for the construction of the drive arrangement ifan eccentric component has two components, which are arranged about theassociated guide region. Moreover, it is thereby suitable if first aneccentric component constructed in one piece is produced, which is thendivided into two components. That division can advantageously take placeby splitting, whereby with that process the eccentric component canalready be heat-treated, therefore fully hardened, for example. Thatprocedure has the advantage that an exact positioning of the assembledcomponents is ensured due to the nonuniformity generated at thesplitting points. The components constituting an eccentric component canbe held together by at least a pressed-on or shrink-on assembly. Thatpressed-on or shrink-on assembly can be formed in an advantageous way bythe bearing inner ring of at least one roller bearing pressed onto theeccentric component.

The rotation of the adjusting shaft relative to the drive shaft can takeplace simply through an adjusting motor provided in the region of an endof the drive shaft. That adjusting motor can advantageously be providedon the end of the drive shaft that faces away from the drive motorconnected with the drive shaft. The adjusting motor can advantageouslybe arranged coaxially to the axis of rotation of the drive shaft. Butother embodiments are also possible, in which the adjusting motor isarranged offset relative to the drive shaft.

The adjusting motor setting the eccentricity or the crank radius of aneccentric drive can advantageously have a driving connection with thedrive shaft as well as with the adjusting shaft. It can thereby besuitable for the adjusting motor to rotate with the drive shaft. Inorder to make possible the desired adjustment, it can be suitable if atransmission ratio is present between at least one of the two shafts,namely the drive shaft and the adjusting shaft, and the adjusting motor.That transmission ratio can take place simply by means of a planetarytransmission or a planetary gear set. The electric motor can be providedwith current through slip rings, for example. It can be particularlysuitable for setting the transmission ratio of the transmission if twoplanetary gear sets connected parallel to each other are assembled,which stand in operative connection with the shafts to be rotated toeach other. In order to realize the desired adjustment, a so-called“harmonic drive” transmission can also be utilized.

Although the drive shaft that operates similar to the crankshaft can beconstructed in one piece, it is also possible to construct that shaft asan assembled shaft. For example, a plurality of guide regions cantherefore be screwed together.

Advantageously, the tooth system of the eccentric component and/or thetooth system of the adjusting shaft can be coated and/or surface-treatedto improve their sliding properties. Those tooth systems can beconstructed as helical or straight tooth systems. By the use of ahelical tooth system the friction in the system can be increased, sothat in an extreme case even a self-locking is made possible. Withself-locking no or only a little energy is required to maintain thetransmission ratio. The size or the portion of blocking action of thetooth systems engaging one another can consequently be determined by thecorresponding selection of the tooth angle and consequently adapted tothe respective application.

BRIEF DESCRIPTION OF THE DRAWINGS

Further suitable refinement features of a functional as well asconstructional nature, which can be utilized in a drive arrangement inaccordance with the invention, will be explained in greater detail onthe basis of the following description of the figures. They show:

FIG. 1 a section through a drive arrangement constructed correspondingto the invention with a transmission and an electrical machine,

FIG. 2 a partially shown section in accordance with line II—II of FIG.1,

FIG. 3 an enlarged scale of a detail shown in FIG. 2,

FIG. 4 a constructional variant of an adjusting transmission for settingthe transmission ratio,

FIG. 5 an alternative arrangement of various components of a drivearrangement in accordance with the invention,

FIG. 6 an enlarged representation of a freewheel unit 9,

FIGS. 7 and 8 respective enlargements of a section of the freewheel unitillustrated in FIG. 6 and

FIG. 9 a graph with different linear gradients.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The drive arrangement illustrated in FIGS. 1 to 3 includes atransmission 1 that is constructed as a crank mechanism.

The transmission 1 has a housing 2, which can be connected with a drivemotor, for example an internal combustion engine of a motor vehicle.

The transmission 1 of the drive arrangement furthermore has a drivenshaft 3, which here forms the transmission input shaft, as well as adriven shaft 4, which here forms a transmission output shaft.

Both shafts 3 and 4 are rotatably supported in the transmission housing2 and are oriented parallel to each other.

Both shafts 3 and 4 are drivingly connected with each other. Thatconnection takes place by means of an eccentric drive 5 provided on thedriven shaft 3 and a freewheel system 6 provided on the driven shaft 4,which are drivingly connected with each other at least through aconnecting element 7, which is here constructed like a connecting rod.

In the illustrated embodiment, the eccentric drive 5 has a plurality ofeccentric units 8 arranged axially side by side about the driven shaft3.

The freewheel system 6 has a plurality of freewheel units 9 arrangedaxially one after the other about the driven shaft 4.

To form an eccentric unit 8, the driven shaft 3 carries or has a guideregion 11 arranged eccentrically relative to the axis of rotation 10 ofthat driven shaft 3, on the surface area of which an eccentric component12 is rotatably or swingably supported. At least one connecting element7 is rotatably or swingably received on the eccentric component 12,which is here constructed as a connecting rod. The support of the atleast one connecting rod 7 takes place in the illustrated embodimentthrough a roller bearing 13, which is here formed by a single-row ballbearing.

The eccentric components constructed ring-like or disk-like are, as canbe especially derived from FIG. 1, constructed in such a way that theycan accommodate two connecting rods 7 arranged axially alongside eachother together with the corresponding support. The angular orientationof two such connecting rods 7 of the transmission, and articulation onthe respective associated freewheel unit 9 is apparent from FIG. 2.

It can be derived particularly from FIG. 2 that an eccentric component12 has a recess for receiving a guide region 11. The eccentric component12 thereby has an inner tooth system 14 arranged about the recess. Theinner tooth system 14 is thereby matched relative to the outer surfacearea of the corresponding eccentric guide region 11 in such a way thatthe eccentric component 12 is centered on the guide region 11 throughthe sections of the inner tooth system bounding the addendum circle ofthe inner tooth system 14.

The driven shaft 3 or the guide regions 11 formed by it have a recess 15extending in the direction of the axis 10 which receives an adjustingshaft 16. The adjusting shaft 16 is supported in the recess 15 in theillustrated embodiment. As is apparent especially from FIG. 3, theadjusting shaft 16 has an outer tooth system 17 whose teeth engage theteeth of the inner tooth system 14 of the eccentric component 12. Theadjusting shaft is centered or supported in the recess 15 of the drivenshaft 3 through the sections of the outer tooth system 17 forming theaddendum circle of the outer tooth system 17.

As is also apparent from FIG. 3, the guide regions 11 belonging to thedriven shaft 3 that are arranged eccentrically relative to the axis ofrotation 10 of that shaft 3 are constructed in such a way that therecess 15 is open over a certain angular region so that in that regionthe tooth system 17 of the adjusting shaft 16 can extend radiallyrelative to the outer surface of the guide region 11, whereby engagementwith the tooth system 14 is made possible.

When a number of “n” guide regions 11 are present, they are preferablydistributed about the adjusting shaft 16, or about the axis of rotation10, in such a way that the angular offset in the peripheral directionbetween two successive guide regions 11 amounts to 360°/n. Six guideregions 11 are apparent from FIG. 1, for example, so that thepreviously-mentioned angle of 360°/n therefore amounts to 60°. The guideregions 11 respectively succeeding one another about the shaft 3 neednot thereby immediately follow in the axial direction of the adjustingshaft 16 or the driven shaft 3, but the axial sequence of the individualguide regions 11 can be selected corresponding to requirementsconcerning stability, dynamics, and other parameters.

As can be derived from FIGS. 1 to 3, the two shafts 3 and 16 arecoaxially arranged relative to the axis of rotation 10 of the drivenshaft 3. Therefore that means that the driven shaft 3 and the adjustingshaft 16 can rotate about the same axis of rotation 10.

It can be derived from FIG. 3 that the guide regions 11 formed disk-likehave a centerline 18 relative to their annular or cylindrical outersurface, which is arranged eccentrically by the distance 19 relative tothe axis of rotation 10.

Furthermore, it can be deduced from FIG. 3 that the eccentric components12 have a centerline 21 relative to their outer annular surface 20,which is arranged eccentrically relative to the centerline 18 of theguide regions 11 at a distance 22. The individual components 16, 3 and12 are thereby coordinated with one another in such a way that thedistance 19 corresponds to the distance 22, so that therefore theeccentricity of the centerline 21 is twice as large relative to the axisof rotation 10 as the eccentricity of centerline 18 relative to thataxis of rotation 10.

The relative position between the individual components or componentregions 16, 11, and 12 illustrated in FIG. 3 therefore produces themaximum stroke that an eccentric unit 8 can transmit to the connectingrods 7 supported thereon. That stroke corresponds to double the sum ofthe distances 19 and 22.

By rotating the shaft 16 relative to shaft 3, the eccentric component 12of an eccentric unit 8 rotates or swings about the corresponding guideregion 11 through the interengaging tooth systems 14, 17. The rotationor swing axis thereby corresponds to centerline 18. By that rotation ofshaft 16 the centerline 21 moves along a circle with the center 18 and aradius corresponding to the distance 22 or 19. That circular movement ofthe centerline 21 is indicated in FIG. 3 by arrow 23.

It is apparent from FIG. 3 that on the basis of a displacementcorresponding to arrow 23 of the centerline 21 about the center point orcenterline 18 a reduction of the distance between the centerline 21 andthe axis of rotation 10 takes place. That means that the eccentricity ofthe eccentric components 12 relative to the axis of rotation 10 isreduced, and consequently the stroke transmittable to the connectingelements or connecting rods 7 is also reduced.

On the basis of the coordination here present between the two distances19 and 22, the centerline 21 can be brought coaxial to the axis ofrotation 10 through a rotation of the centerline 21 about the centerline18 corresponding to an angle of 180°. That means that the annular outersurface 20 of an eccentric component 12 has the axis of rotation 10 ofshaft 3 as the center or median axis, so that then no more eccentricityis present. Consequently, also no stroke movement can be transmitted tothe connecting element 7. That therefore means that, although shaft 3 isbeing driven, the driven shaft 4 or the output shaft of the transmission1 can be stationary.

The input shaft 3 of the transmission 1 constructed crankshaft-like hasan end pin 24 for connection with a drive engine. That end pin 24 isexternally geared in FIG. 1 and receives the hub of a torsionalvibration damper, which is drivingly connected with a flywheel of a notfurther illustrated internal combustion engine. An adjusting mechanism25 is provided on the side of the transmission input shaft 3 facing awayfrom the end pin 24 or the engine, which here is only schematicallyindicated. The adjusting shaft 16 can be rotated relative to thetransmission input shaft 3 through the adjusting mechanism 25, wherebythe gear ratio condition of the transmission 1 is changed. Asillustrated in FIG. 1, the adjusting mechanism can be providedconcentrically relative to the axis of rotation 10 and be rotatableabout that axis 10. The adjusting mechanism 25 can have an electricmotor 26, for example, which is merely illustrated schematically. Theconstruction of the adjusting mechanism is thereby undertaken in such away that the rotor is drivingly connected with one of the two shafts 3,16, and the stator is in driving connection with the other of the twoshafts 16, 3. Those connections can take place, for example, by means ofgears, which can form planetary drives. In FIG. 1, thepreviously-mentioned driving connections are realized with shafts 3, 16by means of two planetary sets 27, 28 connected in parallel. With theillustrated embodiment, the planetary sets 27, 28 are constructed andarranged in such a way that a sun gear is rotatably connected with shaft3, and the other sun gear with shaft 16.

The adjusting mechanism 25 can nevertheless also have a so-called“harmonic drive” transmission.

In the illustrated exemplary embodiment in accordance with FIG. 1, thetransmission input shaft 3 constructed crankshaft-like is formed in onepiece. A shaft 3 of that type could nevertheless also be composed ofseveral components arranged axially one behind the other, which arerigidly connected with one another. Therefore, for example, severalguide regions 11 produced as individual components can be connected withone another, which can, for example, take place through screwedconnections. In addition to those screwed connections, positive-lockingconnections that can be formed by interengaging profiles can beprovided. A welded construction would likewise be possible.

When utilizing a one-piece transmission input shaft 3, the eccentriccomponents 12 must be divided into at least two structural elements 29,30 (FIG. 3) so that they can be mounted about the guide regions 11. Thatcan take place, for example, in that the individual eccentric components12 are first produced in one piece and preferably also heat-treated, andare only afterward divided into two components, for example bysplitting. The fracture sites 30 a generated by the splitting areapparent in FIG. 3. Although threaded and/or pinned connections can beprovided for holding two components 29, 30 together, in manyapplications it may suffice if the components 29, 30 associated witheach other are held together by at least one roller bearing received onthe outer surface 20. For that purpose, for example in the illustratedembodiment, the inner rings of the two one-row ball bearings 13associated with an eccentric component 12 can be pressed on and/orshrink fitted to the eccentric component 12 composed of two structuralelements 29, 30. Exact positioning of two structural elements 29, 30 canalso be ensured on the basis of the roughness present in the region ofthe fracture sites 30 a.

The interengaged tooth systems 14, 17 can be constructed as straightteeth or, however, also as helical teeth. By utilizing helical teeth,the friction in the system or between the intermeshing tooth systems canbe increased. The friction present in the entire system is therebydependent upon the angle of the helical teeth. The helical teeth canthereby be constructed in such a way that in the entire system of theeccentric drive 5 self-locking practically occurs, so that thenpractically no energy is necessary in order to maintain the transmissionset ratio. With a design of that type, nevertheless more power or energyis then necessary for adjusting the system or the eccentric drive 5. Theuse of helical teeth therefore makes possible a design of the degree oflocking in the eccentric drive 5 that is adapted to the respectiveapplication.

In order to at least reduce dynamic forces within the transmission 1, itcan be suitable if compensating masses would be provided at each end ofthe crankshaft-like transmission input shaft 3, through which thepossibly existing free torques or free forces can be balanced. Thoseadditional masses can be similarly constructed and arranged about theaxis of rotation 10 of the shaft 3 like the eccentric components 12. Theadditional masses can therefore, similar to the eccentric components 12,change their effective radius, therefore their eccentricity relative tothe axis 10. In that way, it is possible for all masses at least onshaft 3 to be balanced, at least when setting a crank radius or aneccentricity of zero. A crank radius of zero means that the centerlineor the center axis 21 is situated in a position that is coaxial to theaxis of rotation 10.

An electrical machine 31, which can be designed as a generator and/or amotor, is provided in connection with the embodiment of a drivearrangement illustrated in the figures, as is especially apparent fromFIG. 1. To the extent that the electrical machine 31 is also operable asa motor, it can serve as a starter for the internal combustion enginethat is coupled to the shaft pin 24. Furthermore, that electricalmachine 31 can serve as an auxiliary drive for the motor vehicleoutfitted with such a transmission. For that purpose, correspondingfreewheels or couplings are provided that, if need be, also enabledecoupling of the electrical machine 31 from the internal combustionengine from time to time so that, if need be, the internal combustionengine can also be shut down during travel of the motor vehicle. Theelectrical machine 31 can enable hybrid operation of the motor vehicle.

As is apparent from FIG. 1, in the depicted embodiment the electricalmachine 31 is arranged coaxially to the axis of rotation 10 of thetransmission input shaft 3, whereby the stator 32 is accommodated by ahousing part 33 that is rigidly connected with the transmission housing2 or can form a constituent of that transmission housing 2. Themechanical transmission including the eccentric drive 5 is separatedfrom the electrical machine 31 by a partition 34. The rotor 35 of theelectrical machine 31 is here rotatably supported in the housing 2 or inthe housing part 33 and selectively connectable with the transmissioninput shaft 3 and/or with a gear 38 rotatable relative to shaft 3through couplings, which here are constructed as freewheels 36, 37. Thegear 38 is drivingly connected with the transmission output shaft or theshaft 4 to be driven, which takes place through two gears 39, 40 in theillustrated embodiment. The gear 40 is thereby arranged concentricallyto shaft 4 and the gear 39 serves as a connecting element between thetwo gears 38, 40.

The transmission ratio included in gears 38, 39 and 40, which ensures adriving connection between the rotor 35 of the electrical machine 31 andthe shaft 4, is preferably constructed in such a way that duringgenerator operation of the electrical machine the rotor 35 rotates witha rotational speed which is at least equally high or is higher than therotational speed of the engine with which the shaft 3 is driven. To theextent that the rotor 35 rotates at a higher rotational speed than theengine driving the shaft 3, the drive of the rotor 35 can take placeproceeding from the shaft 3 through the connecting element 7 on theshaft 4 and from there through the transmission ratio included in gears38, 39, 40 to the rotor 35. With a drive of the electrical machine 31 inthat way, the coupling means, which are here formed by freewheels 36,37, are connected in such a way that no direct drive between the shaft 3and the rotor 35 is present. In that way, blockage of the entire drivesystem can be avoided.

The driving connection between the rotor 35 and the shaft 4 can alsotake place by means of a chain or belt drive. Furthermore, it can besuitable if the driving connection between rotor 35 and shaft 4 permitsa variable transmission ratio, whereby that variation can take placestepwise or continuously. With a continuously possible variation of thetransmission ratio condition of the driving connection between the rotor35 and the shaft 4, so-called belt-driven, conical pulley transmissionscan be installed in an advantageous manner. Transmissions of that typecan be selectively regulated or controlled as a function of operatingparameters of the internal combustion engine or the drive arrangement.That can take place, for example, through hydraulic and/or electricalmeans. Nevertheless, it is also possible to install belt-driven, conicalpulley transmissions that undergo a variation in transmission ratiothrough centrifugal-force-dependent means.

The coupling means 36, 37, which on one hand ensure a driving connectionof the rotor 35 with the shaft 3, therefore practically directly withthe drive engine, and on the other hand with the output side of thetransmission, in the present embodiment with the shaft 4, are preferablyconstructed in such a way that, at least when operating the electricalmachine 31 as a generator, the rotor 35 is driven by the faster drive.In that way it can be ensured that especially with a fixed transmissionratio between the output side of the transmission, namely here betweenthe shaft 4 and the rotor 35, when the shaft 4 is rotating slowly oreven standing still, the rotor 35 can be driven directly from the driveengine—by connection of the shaft 3—therefore by the internal combustionengine of the motor vehicle.

To the extent that the electrical machine 31 is operated as a motor, itcan also serve for starting the engine that drives the shaft 3. Withsuch a mode of operation of the electrical machine 31, the drivingconnection to the output side of the transmission, therefore to theshaft 4, is preferably interrupted. That can take place, for example, bymeans of a switchable coupling unit 37.

In the illustrated embodiment in accordance with FIG. 1, atransmission-ratio-free drive of the rotor 35 is possible by means ofthe shaft 3 driven by the internal combustion engine. It can also besuitable, however, to provide a transmission unit between the rotor 35and the internal combustion engine, which enables a change in therotational-speed-related transmission ratio condition between theinternal combustion engine and the rotor 35. That can take place througha shiftable gear drive having at least two stages or, however, by meansof variable transmissions. A transmission unit or such a transmission ofthat type can be provided, for example, between the rotor 35 and theshaft 3.

The adjustment mechanism 25 for the eccentric drive 5 is arranged in aparticularly space-saving manner within the at least partially hollowformed rotor 35.

The electrical machine 31 can advantageously have an output in the orderof magnitude between 2 and 15 kW, whereby it is suitable for manyapplications if the output of the electrical machine 31 amounts to atleast 5 kW. With a sufficiently large output-wise proportioning of theelectrical machine 31, it can at least also serve as drive assistancefor a motor vehicle. Furthermore, the electrical machine 31 can thenalso be relied upon as a brake for the motor vehicle. In that way, itbecomes possible to ensure a braking action through the electricalmachine 31 when descending a mountain or also during deceleration of themotor vehicle, which cannot be realized by the transmission 1 on thebasis of its constructional configuration. When utilizing the electricalmachine 31 as a retarding member, therefore as a brake, it is driventhrough the drive connection including gears 38, 39, 40. In operatingconditions in which the electrical machine 31 serves as a retarding unitfor the motor vehicle, the rotor 35 can be coupled directly or throughthe shaft 3 with the internal combustion engine, so that the internalcombustion engine can also produce a braking torque. With an operatingmode of that type, the braking actions of the electrical machine 31 andthe engine or the internal combustion engine are added. The resultingbraking torque is thereby directed through the driving connectionbetween rotor 35 and shaft 4 including the gears 38, 39, 50.

To the extent the engine driving the shaft 3 and the electrical machine31 simultaneously ensure a drive of the motor vehicle, the power outputprovided by the electrical machine 31 can be transmitted to the shaft 4through gears 38, 39, 40, and the power output from the engine istransmitted to shaft 4 by means of the eccentric drive 5 and thefreewheel apparatus 6.

The drive arrangement in accordance with the invention therefore enablesa plurality of possible connections for the drive or the retardation ofa motor vehicle by means of the electrical machine 31 and/or theinternal combustion engine of the motor vehicle, whereby the connectionpossibilities described relative to driving can also be only partiallyprovided.

Advantageously, the transmission ratio unit that operates parallel tothe transmission 5, which, for example, can be formed by gears 38, 39,40, can have a transmission ratio condition from 2 to 6, whereby it canbe especially suitable for many applications if that transmission ratiocondition amounts to about 4. With a transmission ratio condition of 4,the rotor of the electrical machine 35 can therefore have four times therotational speed of shaft 3.

As can be concluded from FIG. 2, the shaft to be driven or thetransmission output shaft 4, which is rotatably supported in the housing2, has a polygonal profile radially outwardly, which is here formed as ahexagon.

The individual freewheel units 9 have clamping bodies 41, which are hereformed by rollers. The rollers are arranged between an inner ring 42,here formed by a region of the shaft 4, and an outer ring 43, wherebythe surfaces 44, 45 of the outer and inner rings 43, 42 are coordinatedwith each other in such a way that the clamping bodies 41 can block thatrotation at least in one relative rotation direction between inner ring42 and outer ring 43, so that then both rings 42, 43 are rotatedcollectively. No blocking action is produced by the clamping bodies 41in the other relative rotation direction between the two rings 42, 43.The individual clamping bodies or rollers 41 are acted upon preferablyin the blocking direction, which can take place through at least onespring element. Furthermore the clamping bodies 41 are preferablypositioned to each other in the peripheral directions by at least oneretainer.

It can be especially advantageous if the freewheel system 6 or theindividual freewheel units 9 can be switched, therefore the blockingdirection of the clamping bodies 41 can be switched relative to bothrotatable rings 42, 43. By the use of freewheel units of that type, thedirection of rotation of the shaft 4 can be changed in a simple mannerin transmission 1, and consequently a reverse gear, for example, can berealized.

As can be concluded in particular from FIG. 2, the outer ring 43 of afreewheel unit 9 has a link region 46, which here is formed by aprojecting cam of the outer ring 43. The end 47 of a connecting rod 7 isswingably or rotatably supported relative to the link region 46 aboutthe axis 46 a. As can furthermore be concluded from FIG. 2, the twoconnecting rods associated with an eccentric component 12 are arrangedin such a way that the arms 49 extending between the bearing outer rings48 and the ends 47 are arranged symmetrically relative to a straightline 51, which runs through the axis of rotation 50 of the shaft 4 andthe momentary position of the centerline 21 of the eccentric component12. The bearings or ends 47 of two connecting rods 7 associated witheach other likewise continuously have a symmetrical arrangement relativeto straight line 51.

It can be advantageous if the synchronization of the individualcomponents takes place in such a way that the two link regions 46 or theaxes 46 a of the connecting rods 7 associated with each other are atleast approximately diametrically opposed relative to the axis ofrotation 50 in those rotational positions of an eccentric unit 8 inwhich the centerline 21 of the eccentric component 12 has the smallestspacing relative to the axis of rotation 50. The angle existing in thatposition of the centerline 21 relative to the axis of rotation 50, andrelating to that axis of rotation 50 between the two link regions 46 orthe two axes 46 a, can nevertheless be smaller than 180°, whereby ifneed be it can be advantageous for many applications if that angle isgreater than 180°.

As can additionally be concluded from FIG. 1, the shaft 4 forms theinput or drive shaft for a differential 52 that can be arrangedlaterally or beneath the engine connected with the shaft 3. The twooutput shafts 53, 54 are arranged coaxially to the shaft 4, whereby theshaft 54 is received, and if need be supported, inside the shaft 4formed as a hollow shaft.

In the illustrated embodiment, the shaft 4 and the differential cage 55are illustrated in one piece for simplification of FIG. 1. Nevertheless,in practice several parts connected with one another are provided.

Furthermore an inertial mass 56 connected with the shaft 4 is provided,through which the torsional vibration behavior of the transmission 2 canbe influenced.

It can be particularly advantageous for the functioning of thetransmission 2 if the number of eccentric units 8 is even. Six eccentricunits 8 and twelve connecting rods 7 are present in the illustratedembodiment.

As can be deduced from FIG. 1, for weight reduction purposes theeccentric components 12 are at least in partially formed as hollowbodies, whereby an I-shaped cross-section results for the eccentriccomponents 12 illustrated.

Through the constructional configuration of the eccentric drive 5 andthe freewheel system 6 of the invention, the conception of atransmission which has small rotational irregularities withsimultaneously high excitation frequency is made possible. In that way,the possibility of dimensioning the inertial mass or centrifugal mass 56connected with the output shaft 4 comparatively small or slight isproduced. The previously-mentioned advantages are attained bydistributing the output to be transmitted to a large number ofcomparatively lightly formed eccentric units 8 or freewheel units 9.

Because of the construction of the transmission 1, the latter produces anon-uniform rotational motion similar to an internal combustion engine,which is attributable to the kinematics of the transmission. Thenon-uniform rotational motion arises through the superposition ofsine-like crank speeds, which are generated by the eccentric units 8arranged axially alongside one another, which act similar to a crank.The non-uniformity of rotational motion mentioned is thereby a functionof the number of eccentric units 8. The more such eccentric units 8 thatare provided and preferably arranged evenly relative to one another andoffset relative to the axis of rotation, the more constant therotational motion becomes.

In order to ensure the use of drive arrangements or transmissions inaccordance with the invention, the oscillations that are generated byunsteady rotational motions must be reduced to an acceptable extent.That is necessary to avoid torque fluctuations in the drive train of themotor vehicle that impair riding comfort or to reduce them at least to atolerable extent. A particularly effective measure in that regardresides in coupling an inertial mass or a flywheel 56 with the outputshaft 4 of the transmission 1. The connection between the inertial mass56 and the output of the transmission 1, which is here formed by theshaft 4, can thereby take place directly. The inertial mass 56 and theshaft 4 can also be rigidly connected with each other, as can be deducedfrom FIG. 1. For the sake of simplicity, the inertial mass 56 and theshaft 4 are illustrated in one piece in FIG. 1. Of course, however, theinertial mass 56 can be formed by at least one separate component, whichis connected with shaft 4 in a known way, for example by welding,riveting, screwing or wedging.

The inertial mass 56 can also be formed as a damper or a pendulum. Forexample, the inertial mass 56 can have pendulum masses for that purpose.The inertial mass 56 can also have mass components that are connectedwith an inertial component of the inertial mass 56 through springsand/or friction devices.

It can also be advantageous if the inertial mass 56 has a torsionalvibration damper, which is functionally active between the shaft 4 andthe differential 52 or the output shafts 53, 54. In an advantageous way,the inertial mass 56 can also be formed as a so-called two-massflywheel, whereby the one mass can be functionally rigidly connectedwith the shaft 4 and the other mass can be functionally rigidlyconnected with the differential 52 or the output shafts 53, 54.

It is especially suitable if the inertial mass 56 is formed ordimensioned in such a way that in normal driving operation of the motorvehicle the natural frequency of the “resulting spring,” which arises onthe basis of flexibilities in the region of the freewheel units 9, theconnecting rods 7, and the other components situated in the torquetransmission train, is smaller than the excitation frequency of thetransmission 1. In the case of the previously-mentioned naturalfrequency of the “resulting spring,” the effect of the inertial mass 56should be taken into consideration.

To the extent that the previously-mentioned “resulting spring” has asoft characteristic and the inertial mass 56 is dimensioned sufficientlylarge, the irregularities of the engine can also be damped, at least athigh transmission ratios of the transmission 1. The damper between theengine and transmission can then basically only serve for a centraloffset compensation between the engine output shaft and the transmissioninput shaft. The previously-mentioned high transmission ratios arenecessary when starting a motor vehicle. The transmission ratioaddressed here moreover relates to the ratio between the rotationalspeed on the output shaft of the engine to the rotational speed of thewheel drive shafts 53, 54 or the wheels themselves. Thepreviously-mentioned high transmission ratios lie in the order ofmagnitude of from 12:1 to 15:1 in ordinary motor vehicles.

It can be suitable if in addition to the inertial mass 56 a so-calledtwo mass flywheel is provided between the internal combustion engine 270and transmission 1, 201 (see FIG. 5), that thereby through its presencemakes possible control of the irregularities of the internal combustionengine at small transmission ratios. Transmission ratios in the order ofmagnitude from 4:1 to 2:1 are to be understood as small transmissionratios, whereby here, in turn, the ratio between rotational speed of theengine output shaft and the rotational speed at the wheels is also to beunderstood. Usually that transmission ratio condition lies in the orderof magnitude of from 2.8 to 3.5. Such a two-mass flywheel does not needto be formed as an idle damper, which means therefore that the dampingunit of the two-mass flywheel only needs to be adjusted to the loadrange of the motor vehicle.

In order to obtain a high, effective-mass inertial moment even whenutilizing a comparatively low mass, it can be suitable if that mass isrotatably supported in such a way that it can be driven through a drivewith an increasing speed transmission ratio. The shaft driving such adrive can thereby be the transmission input shaft 3 or the transmissionoutput shaft 4, for example.

For damping the output side oscillations, a friction unit or a dampingunit can also be arranged directly on the drive shaft associated withthe one drive wheel, that becomes operative by rotation of with thedrive shaft, for example.

Mass balancing shafts can also be provided on or in the transmission forthe reduction or elimination of mass forces of the transmission sidecrank drive. Such mass balancing shafts are also utilized in connectionwith internal combustion engines.

A fixed angular relationship can also be present between the internalcombustion engine and the eccentric drive 5, through which theirregularities can be at least partially compensated. That angularrelationship is thereby preferably selected in such a way that theoutput requirement existing on the eccentric drive for driving the motorvehicle is always greatest when the rotational motion of the crankshaftis accelerated due to ignition processes, and vice versa. The outputrequirement existing on the eccentric drive 5 or measurable outputrequirement is a function of the engagement condition of the individualfreewheel units 9 of the freewheel system 6. A correspondingly hightorque should also be available on the crankshaft of the internalcombustion engine, preferably in the conditions in which severalfreewheel units 9 engage, and thereby a higher output measure ispossible on the eccentric unit 5 on the crankshaft of the internalcombustion engine and also a correspondingly high torque is available.In operating conditions in which nevertheless only few freewheel units 9engage, and consequently only a low output can be measured on theeccentric drive 5, it is suitable if the torque generated on thecrankshaft of the internal combustion engine by ignition processes iscomparatively small. In relation to the extreme case in which theinternal combustion engine has only one piston and the transmission hasonly one eccentric unit 8, that means that the freewheel unit 9associated with the corresponding eccentric unit 8 is blocked during acombustion process, therefore transmits torque, whereas thecorresponding freewheel unit 9 operates as a freewheel during acompression process.

In addition, the transmission 1 can be constructed very compactly sincethe shaft 3 to be driven can be coaxially arranged with the crankshaftof an internal combustion engine to be connected with the end pin 24.The shaft 3 can thereby rotate at the same rotational speed as thecrankshaft of the internal combustion engine. Furthermore, the outputshaft 4 of the transmission 1 is practically directly connected with thedifferential 52, and therewith is arranged very close to the shafts 53,54 driving the wheels. Such a construction is especially advantageousfor motor vehicles with a transversely mounted engine and front drive.

In the transmission 101 partially illustrated in FIG. 4, the drivenshaft 103 is assembled from several component parts. Those componentparts include an engine-side drive part 103 a, which forms the end pin124 as well as also an eccentric guide region 111. The drive part 103 ais rotatably supported in the housing 102, as is apparent in FIG. 4. Thecomponent parts forming the shaft 103 furthermore include a plurality ofdisk-like formed guide regions 111 a as well as an end part 111 b, whichis likewise rotatably supported in the housing 102 and forms aneccentrically formed guide region 111 c relative to the axis of rotation110 of the shaft 103. The individual components 103 a, 111 a, and 111 bare arranged axially one after the other and are connected with oneanother, for example through bolted connections 160.

With the exemplary embodiment illustrated in FIG. 4, the eccentriccomponents 112 respectively receive only one connecting element 107.

Two planetary sets 127, 128 connected parallel to each other areprovided for rotating the adjusting shaft 116 relative to the inputshaft 103. The planetary set 127 has a sun gear 161 that isnon-rotatably connected with the shaft 116. The planetary set 128 has asun gear 162 that is non-rotatably connected with the shaft 103. Theplanet gears 163 of the planetary set 127 engage a ring gear 164 that isrotatably supported or received in the housing 102. The planet gears 165of the planetary set 128 operate together with a ring gear 166, which isnon-rotatable relative to the housing 102.

The ring gear 164 is rotatable through a worm gear drive or a worm gear167. The ring gear 164 has a corresponding tooth system therefor. With aconfiguration of that type, the motor provided for adjusting thetransmission gear ratio, such as in particular an electric motor, can bearranged offset relative to the axis of rotation 110. With theillustrated embodiment, the worm gear 167 is constructed in such a waythat the electric motor driving the worm gear 167 is arranged obliquelyrelative to the shaft 103. In the illustrated exemplary embodiment, theplanet gears 163 and 165 have an identical tooth system diameter, but itcan also be suitable if the planet gears 163 have a tooth system thathas another diameter than the tooth system of the planet gears 165.

The connecting rods 7, 49 can also be dimensioned in such a way thatthey are practically rigid at least in the longitudinal direction, thatis, in the direction of a line which connects the two centerlines oraxes 46 a and 21, and therefore have practically no elasticity andthereby experience no or an insignificant deformation during a forcetransmission or a torque transmission.

However, it can also be especially advantageous if the connectingelements or connecting rods 7 are connected in such a way that theyexperience a certain elastic deformation as a function of the forces ortorques transmitted. The deformation increases when the force becomesgreater or with increasing torque.

An elastic design of the connecting elements 7, 49 of that type has theadvantage that certain manufacturing tolerances can be compensated inthat way. Furthermore, such an elasticity has the advantage that thatway it can thereby be ensured that a plurality of freewheel units 9 arein a blocked condition, whereby it will be attained that in each casethe torque to be transmitted can be transmitted by a plurality ofconnecting elements 7, 49 to the shaft 4. During the transmission oftorque, the connecting elements 7, 49 are therefore in an elasticallytensioned condition. On the basis of the elasticity of the connectingelements 7, 49 and the possibly occurring timewise offset of a pluralityof freewheel units 9, the forces or torques transmitted by theindividual connecting elements 7 can vary from one another.

On the basis of the previously-mentioned possible elastic tensioncondition of the connecting elements 7, 49, the freewheel units 9 canstill be in a stressed or blocked condition, although the connectingelement associated with such a freewheel unit 9 is already moving in theunblocking direction of the corresponding freewheel unit 9. Thattherefore means that at least theoretically a freewheel unit 9 onlydiscontinues its blocking function when the corresponding connectingelement is in a relaxed position.

The previously-mentioned operating mode can, if need be, also be ensuredby the introduction of a corresponding elasticity at another position.An elasticity of that type can take place, for example, in the region ofthe connecting rod bearing sites, for example, 46 (see FIG. 1). Anelasticity of that type could, if need be, also be provided in additionto the elasticity of the connecting elements 7. An elasticity of thattype could be realized, for example, by arrangement in the region of thepivot bearing at site 46 of a rubber or plastic ring, which receives theactual bearing, for example.

It can be particularly advantageous for the function of the transmissionif the distance between the two pivot or rotation axes 21, 46 a (seeFIG. 2) of a connecting element 7 is smaller than the distance betweenthe two axes of rotation 10, 50 of the driven shaft 3 and the drivenshaft 4.

Furthermore, it can be especially advantageous for the design of thedrive arrangement if the axis of rotation 46 a of the connecting rod hasa spacing relative to the axis of rotation 50 of the output shaft 4 thatcorresponds to about double the spacing between the axis of rotation 10of the input shaft 3 and the centerline 21 of an eccentric component 12at the maximum set eccentricity. That maximum eccentricity is evident inFIGS. 2 and 3.

As was explained in greater detail particularly in connection with anembodiment in accordance with FIGS. 1 to 3, the freewheels of freewheelunits 9 are provided on the output shaft 4 of the transmission 1 onwhich the drive torque to be transmitted is transmitted by means of theconnecting elements or connecting rods 7. With the exemplary embodimentillustrated in FIG. 1, the support of the shaft 4 takes place at bothshaft ends. The torque is further conducted through thepolygon-like-arranged surfaces 45 of the shaft 4 directly on thedifferential cage 55. By subdividing the connecting elements orconnecting rods 7 into pulling and pushing connecting rods 7, thetransverse forces which act upon shaft 4 are at least partially canceledbased upon the simultaneous engagement of several freewheels, wherebythe forces acting upon the supports of the shaft 4 can at least bereduced.

In order to ensure reverse travel possibility in a motor vehicle whichis ouffitted with a transmission operating according to the principledescribed, a corresponding reverse gear step must be provided betweenthe motor vehicle drive engine and drive shafts 53, 54 for the wheels.For example, a corresponding gear step can be provided for that purposebetween the shaft 4 and the drive wheels. Furthermore, a correspondinggear step can be provided between the drive engine of the motor vehicleor the shaft 3 and the output shaft 4, whereby then the blocking actionof the freewheel units 9 must be discontinued, at least for thoseoperating phases during which reverse travel of the motor vehicle isdesired.

As already described, it is also possible to realize a reverse gearfunction in an especially simple way by means of the freewheel 6, thatis, by equipping the freewheel units 9 with a reversible blockingdirection. A possible construction for configuring a freewheel of thattype is illustrated in FIGS. 6 to 8.

The freewheel unit 9 partially illustrated in FIGS. 6 to 8 has alreadybeen described with respect to its construction principle in connectionwith FIG. 2. The polygonal profile 80 present on the outer periphery ofshaft 4 is constructed in such a way that surfaces 45 forming thatprofile 80 are symmetrically constructed with respect to the blockingfunction or freewheel function of the freewheel 9, which is realizedutilizing the clamping bodies 41.

A switching device 81 is provided for switching the blocking function ofthe freewheel 9, which has several switching units 82 that arerespectively arranged between adjacent clamping bodies 41. The switchingunits 82 are synchronously actuated and have switching means, which eachhave a rotatable, disk-like region 83 as well as a profiled region 84,preferably composed of a profiled bar. A spring is provided in theprofiled region 84, which is formed by a leg spring 85 in theillustrated embodiment. The spring 85 is braceable between the profiledregion 84 and a clamping body 41. For that reason, the leg spring 85 hasa leg 86 that can act against a clamping body 41 in the correspondingblocking direction. The spring element 85 and the profiled regions 84are arranged eccentrically relative to the axis of rotation of thedisk-like regions 83, so that when the disk-like regions 83 rotate, aperipheral displacement of the spring element 85 and the profiledregions 84 takes place. The two peripheral extreme positions of thespring element 85 and the profiled regions 84 are illustrated in FIGS. 7and 8. The disk-like regions 83 are supported in a carrier or housingportion, which is preferably non-rotatable relative to the shaft 4. Itcan be deduced from FIGS. 7 and 8 that the direction of tensioning orthe force direction of the spring element 85 or the spring leg haschanged relative to the clamping body 41 by rotation of the disk-likeregions 83 by about 180°. The position illustrated in FIG. 7 of theindividual components relative to each other can, for example,correspond to the pulling operation of a motor vehicle, so that therelative positions of the individual components which are set forreverse travel of the motor vehicle is then illustrated in FIG. 8. In anadvantageous way, the contoured profiled regions 84, as alreadymentioned, can be formed bar-like, whereby those profiled bars 84 canextend axially through all freewheel units 9, in accordance with FIG. 1,so that by rotation of the profiled rods 84 all freewheel units can beswitched at the same time.

The drive arrangement schematically illustrated in FIG. 5 differs fromthat illustrated in FIG. 1 in that the electrical machine 231 is axiallyarranged between the transmission 201 and the internal combustion engine270, of which merely the crankshaft is schematically shown.

The transmission 201 is constructed similar to the transmission 1 inaccordance with FIG. 1, and consequently likewise has an eccentric drive205 as well as at least one freewheel system 206, which nevertheless aremerely schematically shown. The rotor 235 of the electrical machine 231is on one hand connected with the transmission input shaft 203 and thecrankshaft 271 of the internal combustion engine 270 through a frictionclutch 236, and on the other hand can be coupled with the output side ofthe transmission through a friction clutch 237. Between the rotor 235 orthe friction clutch 237 and the output side of the transmission atransmission ratio unit 272 is provided, which is constructed similar tothose which were described in connection with FIG. 1. The transmissionratio unit 272 schematically illustrated in FIG. 5 is formed as a geardrive, which has three gears like the transmission ratio unit inaccordance with FIG. 1 and has a fixed transmission ratio condition,which can lie in the order of magnitude of four. With the illustratedexemplary embodiment, the one gear 240 is carried by the differentialcage 255.

The friction clutches 236, 237 are disengaged and engaged correspondingto the existing operating conditions of the motor vehicle, so that theelectrical machine 231, as described in connection with FIG. 1, canassume various functions, namely, for example, a generator function, astarter function, and/or a braking function.

In the illustrated exemplary embodiment, a flywheel 273 is providedbetween the internal combustion engine 270 and the electrical machine231. That flywheel 273 can be formed as a rigid flywheel, or also can beformed as a so-called two-mass flywheel. When utilizing a two-massflywheel, it can be advantageous if the rotor 235 can be connectedthrough the clutch 236 with that flywheel mass that is non-rotatablyconnected with the internal combustion engine 270. The second flywheelmass, connected with the first flywheel mass through a torsionalvibration damper, is then connected with the transmission input shaft203.

In the schematic representation of a drive arrangement in accordancewith FIG. 5, the adjusting mechanism 25 shown in FIG. 1 for theeccentric drive 205 is not shown. An adjusting mechanism of that typecan be arranged in the embodiment in accordance with FIG. 5 in theregion of the end of the shaft 203 facing away from the engine 270.

Switching the type of drive of the rotor 235, namely from the engineside or from the motor vehicle side, can also take place simply byutilizing two freewheels, which are connected in such a way that therotor 235 can respectively be driven from the faster drive side.

The use of an electrical machine 31 or 231 as a brake made possiblethrough the configuration of a drive arrangement in accordance with theinvention enables a relief of the actual braking system of a motorvehicle, which is especially beneficial in descending a mountain.

When operating the electrical machine as a generator, it can be appliedat least for supporting the normal braking system, as already mentioned.The energy generated produced thereby can also be utilized for heatingthe engine coolant, for example by installing an electrical heater inthe radiator. In that way, kinetic energy of the motor vehicle can bereduced in a simple way. The temperature of the liquid coolant can bemaintained in a simple way at a certain or still acceptable temperatureby turning on the fan. In case it is needed, heat exchangers forming theradiator in motor vehicles of that type can be dimensioned larger, and astronger fan or additional fans can be provided if necessary. At least aportion of the resulting braking energy can therefore—for example at lowoutside temperatures—be utilized by means of the electrical machine formore rapid heating of the liquid coolant of the engine and/or theinterior space of the motor vehicle.

If necessary, an additional current consuming device can be added todissipate the resulting excess electrical energy. Insofar as a separatestarter motor is present, it can be connected and if need be put intooperation so that it attempts to start the engine, therefore to pull italong, whereby nevertheless no fuel is delivered. Other consumingdevices can also be utilized for the dissipation of energy, such as, forexample, glow plugs, radiator blowers, windshield heaters, lighting,etc.

It can also be suitable if during normal travel the state of charge ofthe battery is kept at a level that enables storage of a certain amountof energy. That means, therefore, that during normal travel the state ofcharge of the battery is controlled such that a residual capacity in thebattery is always reserved for braking energy.

As can be deduced from the preceding description, the drive arrangementin accordance with the invention or the transmission constructiondescribed enables the motor vehicle to start traveling from an“infinite” transmission ratio. Nevertheless no retarding torque can betransmitted through the connecting-rod-like connecting elements 7because of the kinematics of the transmission. As likewise has alreadybeen described, components, which transmit the torque existing insidethe transmission, can have a certain elasticity. Those componentsinclude, among others, the connecting elements or connecting rods 7. Onthe basis of those elasticities, the transmission 1 has thecharacteristic that the transmission ratio between shafts 3 and 4 isdependent upon transmitted torque with eccentricity in the region of theeccentric drive 5 constant.

In order to enable a trouble-free utilization of the transmission inaccordance with a further concept of the invention, a control unit isutilized for the drive train or the transmission, in which the torquecurrently transmitted by the transmission is determined on the basis ofthe transmission ratio actually present on the transmission and theeccentricity actually present in the region of the eccentric drive 5.That actually present eccentricity is namely a measure for thetheoretically existing, actual transmission ratio, namely that whichwould be present if practically no torque were being transmitted.Therefore, the existing torque is determined indirectly through theelastic deformations of components of the transmission taking place thatbring about the previously-mentioned change in transmission ratio. Thepreviously-mentioned parameters or values can be stored in a controlunit in the form of a characteristic field or a characteristic curve,whereby in the control unit a signal representing the transmission ratiocan also be processed. The transmission ratio can thereby be learned onthe basis of the ratio between the rotational speed present at thetransmission input side and the torque present at the transmissionoutput side. A comparison between the engine rotational speed and therotational speed of the output shafts or drive wheels of the motorvehicle is also possible.

The torque existing on the wheels can be continuously determined withsuch a method, even when the vehicle is standing. That is, as alreadymentioned, made possible through the fact that each eccentricity or eachcrank radius of the eccentric drive 5 can be associated with acorresponding torque.

The eccentricity actually present at the point of time in question orthe momentary crank radius of the eccentric drive 5 can be determined ina simple way through the difference in the absolute angle of rotationbetween the shaft 3 and the adjusting shaft 16—relative to thestationary housing 2 or 33. That can take place, for example, in thatrotational speed impulses of both shafts 3 and 16 are measured byincremental transmitters, and that by subtraction the relative rotationand therewith the angular position between both shafts 3 and 16 isdetermined. The transmitter wheel of the rotational speed measuring unitcan thereby be provided directly on the adjusting motor 26 in anadvantageous way. That has the advantage that the rotational speedmeasuring unit which is in series with the existing transmission ratiopresent between the adjusting motor 26 and both shafts 3, 16, throughwhich a good resolution exists relative to the eccentricity to bedetermined, since the rotor of the adjusting motor 26 runs through alarge rotation relative to the actual rotation between both shafts 3 and16. In that way, a sufficiently precise measurement of the relativeposition between the individual components is ensured, even whenutilizing a sensor wheel with comparatively few teeth.

A further possibility of determining the crank radius or theeccentricity in the region of the eccentric drive 5 lies in the factthat utilizing a rotational speed or rotation measuring unit that uses aposition sensor that rotates with the adjusting motor 26 or the shafts3, 16 and directly measures the rotation angle between both shafts 3, 16or the components of the motor 26 that can rotate relative to oneanother. The signal representing the corresponding rotation can then betransmitted by radio or slip ring to the control device that processesthat signal.

The position corresponding to a “zero” eccentricity between theadjusting shaft 16 or the driven shaft 3 and the eccentric components 12can be determined on the basis of a rotation stop between the adjustingshaft 16 and the driven shaft 3. That determination can result in thatthe adjusting motor 26 rotates both shafts 3 and 16 in such a way thatthat stop becomes operative. It can thereby be suitable if the change inthe eccentricity of the crank radius is determined simultaneously. In anadvantageous way, the rotation stop operative between both shafts 3 and16 can advantageously be adjustable.

When starting the motor vehicle, starting from an “infinite”transmission ratio, it is advantageous if the wheel torque present onthe drive wheels is regulated corresponding to the driver's wishesthrough the eccentricity of the eccentric drive 5. Thereby the internalcombustion engine can first be throttled through an appropriate controlunit. Through such a method, it becomes possible that only first whenthe actual torque is smaller than the desired torque after driving away,a transition to the usual control strategies of automatic clutches cantake place.

In order to ensure that an at least approximately constant eccentricitycontinues to exist on the eccentric drive 5 or an at least approximatelyconstant gear ratio of the transmission is maintained, it can beadvantageous to control the adjusting motor 26 impulse-like, whereby anundesired, automatic adjustment can be avoided. In an advantageous way,the frequency of the impulses can thereby be selected to be so high thatpossible small changes in transmission ratio occurring between twoimpulses are not detectable in the motor vehicle. Through such a method,the load on the adjusting motor 26 constructed as an electric motor canalso be reduced. In that way it also becomes possible to operate theelectric motor better as to the degree of efficiency.

To the extent it should be necessary to reduce or to influence thefriction between the interengaging tooth systems 14 and 17, that cantake place by means of the adjusting motor 26 in that that adjustingmotor is controlled so that at least the shafts 3 and 16 are moved backand forth relative to each other, and, to be sure, preferably by such asmall amount that a practically constant transmission ratio conditioncan be ensured. Those back and forth movements also make it possible tobuild up a lubricant film between the corresponding contact regions.

It can be especially advantageous if the motor vehicle equipped with adrive arrangement in accordance with the invention has a brake, forexample an electrical parking brake, that is engaged when the motorvehicle is stationary and the accelerator is not actuated to avoid atwisting of the freewheels 9.

Furthermore, it can be especially advantageous if when slowing the motorvehicle the transmission ratio of the transmission is set somewhatshorter than that transmission ratio which would arise from the enginerotational speed and the driving speed with “zero” load. That somewhatshorter transmission ratio is thereby continually adapted to the drivingconditions determined by the engine rotational speed and the drivingspeed. By deceleration of the motor vehicle, rolling to a stop orbraking the motor vehicle are to be understood. The latter can beespecially easily set through the previously-mentioned adjustment of thetransmission ratio of the transmission, and the motor vehicle has thecorrect transmission ratio when gas is reapplied, that is, inreaccelerating the motor vehicle. To the extent that thepreviously-mentioned transmission ratio adjustment is not possiblewithout something further in certain operating conditions of the motorvehicle, for example at a relatively rapid driving speed (above 80 km/h)and with an engine rotating at idle speed, it can be particularlysuitable to regulate or control the engine rotational speed and/or theengine torque so that in rebuilding a driving torque that torque builduptakes place smoothly. A similar regulation or control is also suitableif the engine is shut down in slowdown phases of the motor vehicle.

In a motor vehicle with a drive system arranged in accordance with theinvention, it can be advantageous if it has a control unit which enablesa starting strategy as described below in connection with FIG. 9.

In the graph in accordance with FIG. 9, time is illustrated on theabscissa, on the left ordinate the wheel or engine rotational speed, onthe right ordinate the wheel or engine torque.

The characteristic curve 380 represents the course of the enginerotational speed. The characteristic curve 381 represents the wheelrotational speed of the motor vehicle multiplied by 10. Thecharacteristic curve 382 represents the course of the required enginetorque, and the characteristic curve 383 corresponds to the torquecourse on the drive wheels.

It can be deduced from FIG. 9 that the starting process of a motorvehicle includes 3 partial regions, specifically of a first, 384, inwhich the wheel torque existing on the wheels is controlled, a second,385, in which the engine rotational speed is regulated, as well as athird, so-called transition region 386, which is provided between thefirst and the second region. The transition region 386 can last more orless long depending upon the application case.

The torque 383 existing on the wheels in the first region 384 is setover time. The target values of the torques are stored in acharacteristic field, whereby the selection from the characteristicfield takes place corresponding to the driver's wishes. The momentarydriver's wish can essentially be determined by the accelerator pedalangle and the speed of activation of the accelerator, thereforepractically the desired amount of fuel. A correspondingly rapidoperation of the accelerator is transformed into a correspondinglyadapted torque buildup, and the reverse. The existing or possible rateof torque buildup in region 384 is essentially determined by the maximumspeed of adjustment of the transmission 1.

The absolute target wheel torque arising during a startup process isderived from the accelerator angle, and indeed in such a way that aharmonious course of the wheel torque results during the transition tothe second region 385 of the start up procedure.

By specifying the wheel torque over time, the necessary engine torquedepends only on the actual transmission ratio over time. In that way,the engine torque is also dependent upon the rolling resistance and mustbe regulated corresponding to demand. If for example the rollingresistance is very high and the motor vehicle does not move despiteapplied wheel torque, then the gear ratio remains infinite and thenecessary engine torque very small. If the rolling resistance is verysmall, for example in driving downhill, then the engine torque must bebuilt up more rapidly. If deviations in wheel or engine torque arise,then either only one or both magnitudes, namely engine torque andtransmission ratio, can be subsequently corrected. During a startupprocess, the engine rotational speed course 380 is oriented in agreementwith the subsequent travel rotational speed. That means that the enginerotational speed does not show any overshoot in starting up, but ratherapproaches the target travel rotational speed in a freely selectablefunction. To the extent that an increase in rotational speed is desiredin the first partial region 384, one can select the engine torquesomewhat higher in order to attain an initial acceleration of theengine.

In the second region 385, the transmission is regulated according to theknown regulation for stepless transmissions during a startup process.Thereby the engine rotational speed is essentially regulated by thetransmission ratio of the transmission.

In order to obtain a harmonious course of torques and rotational speeds,control components can be reduced in transition region 386 and theregulation components can be utilized to a higher degree. The middle orthe center of the transition region 386 lies at the position on whichthe necessary engine torque is as large as the maximum torque availablefrom the engine at the moment, which is dependent upon the momentaryrotational speed and the accelerator angle setting.

Insofar as the driver changes his desired torque during a startupprocess, a corresponding new operating point is directly approached. Thespeed or the period of time in which the new operating point isapproached results from the speed of accelerator change, among otherthings.

The previously-mentioned starting strategy can especially be utilized inmotor vehicles whose internal combustion engine is operated by means ofa so-called electronic gas pedal, or by means of a gas pedal that isconnected with the fuel supply system through an electronic unit.Furthermore, it is advantageous if a so-called interface exists betweenthe internal combustion engine and the transmission.

With a so-called full-load start, the target torque existing on thewheel should essentially not be above a torque causing the wheels toslip. In an advantageous way, the engine rotational speed canimmediately or very rapidly be driven to the maximum so that the fullengine power is available from the equilibrium point of the twopreviously-mentioned torques.

With the startup strategy in accordance with the invention, the torquebuildup can advantageously be initiated immediately with the incipientmotion of the accelerator.

The patent claims submitted with the application are formulationproposals without prejudice for attaining more extensive patentprotection. The applicant reserves the right to claim additional featurecombinations previously disclosed only in the description and/ordrawings.

References utilized in the dependent claims refer to the furtherdevelopment of the object of the main claim through the features of therespective dependent claim. They are not to be understood as a waiver ofattaining an independent, objective protection for the featurecombinations of the referred-to dependent claims.

Since the objects of the dependent claims could, with respect to thecondition of the art on the priority day, form their own and independentinventions, the applicant reserves the right to make them the objects ofindependent claims or statements of division. They can furthermore alsocontain independent inventions, which have a configuration independentof the objects of the preceding dependent claims.

The exemplary embodiments are not to be understood as a restriction ofthe invention. Rather, numerous changes and modifications are possiblein the framework of the present disclosure, especially such variants,elements and combinations and/or materials which can, for example, bededuced by the specialist with regard to the solution of the object bythe combination or modification of individual features or elements orprocedural steps in connection with the general description andembodiments as well as described in the claims or contained in thedrawings, and which lead by combinable features to a new object or tonew procedural steps or procedural step sequences, also to the extentthat they concern manufacturing, testing and operating procedures.

1. A drive arrangement for a motor vehicle having at least onetransmission driveable by an engine having a drive shaft and whichtransmission has a driven input shaft coupleable with the engine as wellas at least one driven output shaft drivingly connected with the inputshaft, said drive arrangement comprising: an eccentric drive provided onthe input shaft, an actuation unit operatively connected with theeccentric drive for adjusting the eccentric drive, and a blockablefreewheel unit provided on the output shaft, wherein the eccentric driveand the freewheel unit are connected with each other through at leastone connecting element, and an electrical machine selectively drivinglyconnected through shiftable coupling means with one of the output shaftof the transmission, with the engine, and simultaneously with both theoutput shaft and the engine.
 2. A drive arrangement in accordance withclaim 1, wherein the electrical machine is connected with the outputshaft of the transmission through a transmission ratio unit.
 3. A drivearrangement in accordance with claim 1, wherein the electrical machineis connected with the engine at least during deceleration of the motorvehicle.
 4. A drive arrangement in accordance with claim 1, whereinduring driving conditions of the motor vehicle in which the electricalmachine is connected with the output shaft of the transmission as wellas with the engine torque flow between the output shaft and the engineis conducted through the electrical machine.
 5. A drive arrangement inaccordance with claim 1, wherein a connection of the electrical machinewith the output shaft of the transmission takes place duringdeceleration of the motor vehicle.
 6. A drive arrangement in accordancewith claim 1, wherein during deceleration of the motor vehicle theelectrical machine is driven by means of the transmission ratio unitfrom the output shaft of the transmission.
 7. A drive arrangement inaccordance with claim 6, wherein during deceleration of the motorvehicle, the engine is driven by connection of the electrical machinefrom the output shaft of the transmission.
 8. A drive arrangement inaccordance with claim 1, wherein the electrical machine is drivinglyconnected with the output shaft of the transmission through a fixedtransmission ratio stage.
 9. A drive arrangement in accordance withclaim 1, wherein the electrical machine has a transmission-ratio-freeconnection with the engine.
 10. A drive arrangement in accordance withclaim 1 wherein the electrical machine is operable as a generator.
 11. Adrive arrangement in accordance with claim 1, wherein the electricalmachine is operable as a motor and as a generator.
 12. A drivearrangement in accordance with claim 1, wherein the electrical machineis operable as a starter for the engine and as a generator.
 13. A drivearrangement in accordance with claim 1, wherein the electrical machineis operable for energy recuperation at least during deceleration of themotor vehicle.
 14. A drive arrangement in accordance with claim 1,wherein the electrical machine is operable as a driving engine for themotor vehicle.
 15. A drive arrangement in accordance with claim 1,wherein the electrical machine is disposed coaxially to the input shaftof the transmission.
 16. A drive arrangement in accordance with claim 1,wherein the electrical machine is disposed on a side of the input shaftof the transmission facing away from the engine.
 17. A drive arrangementin accordance with claim 1, wherein the electrical machine is disposedaxially between the engine and the transmission.
 18. A drive arrangementin accordance with claim 13, wherein energy developed duringrecuperation operation of the electrical machine is dissipated by meansof a cooling system of the engine.
 19. A drive arrangement in accordancewith claim 2, wherein the transmission ratio unit provided between theoutput shaft of the transmission and the electrical machine rotates theengine and the electrical machine at their maximum rotational speed atthe highest speed of the motor vehicle.
 20. A drive arrangement inaccordance with claim 2, wherein the transmission ratio unit between theoutput shaft of the transmission and the electrical machine is operableat the maximum speed of the motor vehicle to rotate the electricalmachine at a rotational speed which is greater than the rotational speedof the engine at its highest power output.
 21. A drive arrangement inaccordance with claim 1, wherein the driving connection between theelectrical machine and the output shaft of the transmission and thedriving connection between the electrical machine and the engine eachtake place through a the freewheel unit.
 22. A drive arrangement inaccordance with claim 21, including a pair of freewheels connected todrive the electrical machine by a momentarily faster drive.
 23. A drivearrangement in accordance with claim 1, wherein the shiftable couplingmeans are connected to drive the electrical machine by the momentarilyfaster drive.
 24. A drive arrangement in accordance with claim 1,wherein the actuation unit for adjusting the eccentric drive is coaxialto a rotor of the electrical machine.
 25. A drive arrangement inaccordance with claim 1, wherein the actuation unit is arranged at leastpartially within the at least partially tubular formed rotor of theelectrical machine.
 26. A drive arrangement in accordance with claim 24,wherein the actuation unit includes at least one electric motor.
 27. Adrive arrangement in accordance with claim 1, wherein the eccentricdrive includes a guide region arranged eccentrically relative to theaxis of rotation of the input shaft, on which an eccentric component isrotatably supported, and on which the connecting element is rotatablysupported.
 28. A drive arrangement in accordance with claim 27, whereinthe drive shaft includes an axial recess in which an adjusting shaftengages, through which the eccentric component is rotatable on the guideregion.
 29. A drive arrangement in accordance with claim 27 theeccentric component includes a recess for receiving the guide region.30. A drive arrangement in accordance with claim 29, characterized inthat the eccentric component has an inner tooth system in the region ofthe recess.
 31. A drive arrangement in accordance with claim 30, whereinthe eccentric component is carried on the guide region by a section ofthe inner tooth system bounding the addendum circle of the tooth system.32. A drive arrangement in accordance with claim 28, wherein theadjusting shaft has an outer tooth system.
 33. A drive arrangement inaccordance with claim 32, wherein the adjusting shaft is supported inthe recess of the drive shaft by the section forming the addendum circleof its outer tooth system.
 34. A drive arrangement in accordance withclaim 32, wherein the inner tooth system of the eccentric component isin engagement with the outer tooth system of the adjusting shaft.
 35. Adrive arrangement in accordance with claim 28, wherein the adjustingshaft is rotatable relative to the drive shaft and one rotation of theadjusting shaft produces a rotation of the eccentric component on theguide region.
 36. A drive arrangement in accordance with claim 1,wherein at least two eccentric drives are provided on the drive shaftarranged one after the other.
 37. A drive arrangement in accordance withwherein the freewheel unit provided on the output shaft has an outerring on which a connecting element associated with that freewheel unitis swingably articulated.
 38. A drive arrangement in accordance withclaim 28, wherein the axis of rotation of the adjusting shaft and theaxis of rotation of the drive shaft are concentric.
 39. A drivearrangement in accordance with claim 28, wherein rotation of theadjusting shaft relative to the drive shaft takes place through anadjusting motor provided at an end of the drive shaft and associatedwith the actuation unit.
 40. A drive arrangement in accordance withclaim 39, wherein one end of the drive shaft is connected with aninternal combustion engine and the adjusting motor is positioned in theregion of an opposite end.
 41. A drive arrangement in accordance withclaim 39, wherein the adjusting motor is coaxial to the drive shaft. 42.A drive arrangement in accordance with claim 39, wherein the adjustingmotor has a driving connection with the drive shaft and the adjustingshaft.
 43. A drive arrangement in accordance with claim 39, wherein theadjusting motor associated with the actuation unit rotates with thedrive shaft.
 44. A drive arrangement in accordance with claim 39,including a transmission ratio gear unit positioned between at least oneof the drive shaft and adjusting shaft, and the adjusting motor.
 45. Adrive arrangement in accordance with claim 44, wherein the transmissionratio gear unit includes at least one planetary gear set.